Transport of lipids to the plasma membrane in animal cells

Abstract

AB~IAT1ONS 195 I, INTRODUCTION 196 II. Trm CHARACTERISTICS OF PLASMA MEMBRANE LIp .s 196 A. The distinctive lipid composition of plasma membranes 196 B. Is there a universal plasma membrane lipid composition? 197 C. Transbilayer distribution of plasma membrane lipids 198 III. MODES OF LIPID TRANSPORT WlTmN CELLS 198 A. Vesicular transport 198 B. Lipid transport by carrier proteins 199 1. Specificity and activity of LTPs 199 2. Role of fipid transfer proteins in vesicular transport pathways 200 3. Possible effects of unilateral lipid insertion on transport of lipids 201 4. Role of LTPs in PI turnover 202 IV. LIPID SYNI'HmtS AND TRANSPORT TO THE PLASMA MEMBRANE 202 A. Glycerolipids 202 1. Sites of synthesis 202 2. Transport to the plasma membrane 203 B. Sphingomyelin 204 I. Sites of synthesis 204 2. Movement of SM to the cell surface 205 3. The fate of the diacylglycerol residue derived from PC during SM biosynthesis 206 C. Glycosphingolipids 207 I. Sites of synthesis 207 2. Transport of GSLs to the plasma membrane 207 3. Transport of SM and GSLs to the cell surface domains of polarised cells 208 D. Ceramide 208 E. GPI-anchored proteins 209 1. Sites of synthesis 209 2. Movement of GPI anchors to the plasma membrane 210 F. Cholesterol 210 1. Sites of synthesis 210 2. Movement of cholesterol to the plasma membrane 210 V. GENERATION AND MAINTENANCE OF PLASMA MF~SRANE LIPID COMPOSITION AND ASYm~TRY 212 A. Is there a gradient of membrane lipid composition in the secretory pathway? 212 B. Maintenance of plasma membrane lipid composition and asymmetry 213 CONCLUSIONS 214 PROBLEMS YET TO BE SOLVED 215 ACKNOWLEDGEMENTS 215 REFEPaSNCES 215 VI. VII.